Drill-chuck.



PATENTED SEPT. 13, 1904.

am 0 9 l 1 m L 10W HUU U C S I m P N K O 0 H P P A wvm dofe hafies R.Ease a 01130 UNITED STATES Patented September 13, 1904.

PATENT ()FFICE.

DRILL-CHUCK.

SPECIFICATION forming part of Letters Patent No. 769,956, datedSeptember 13, 1904.

Application filed October 5, 1903. Serial No. 175,775. (No model.)

To all whom, it nan/y concern:

Be it known that I, CHARLES R. PASOUCILLO, a citizen of the UnitedStates, and a resident of Bridgeport, in the county of Fairfield andState of Connecticut, have invented certain new and useful Improvementsin Drill-Chucks, of which the following is a specification.

My invention relates to new and useful improvements in chucks or holderssuch as are employed in drills or other machine-tools for retaining tapsand like instruments.

The device, as is obvious, is designed principally to hold aninstrumentas,for instance, a tapwhile running a thread and to allow thesame to automatically stop rotating when the threading of a hole iscompleted, yet permitting the spindle driving the chuck to continuerotating without breaking or injuring the tap, and, further,to againsufficiently grasp the tap to withdraw it when the spindle is reversed.I

It is the object of the invention to simplify, cheapen, strengthen, andgenerally improve the construction of tools of its class; further, toprovide a chuck which can be readily adapted for taps havingdifferent-sized shanks, and, finally, for providing means for settingthe tap at difierent heights, as will be later more fully explained.

With the above objects in view my invention resides and consists in thenovel construction and combination of parts shown upon the accompanyingsheet of drawings, forming a part of this specification, in whichsimilar letters of reference denote like or corresponding partsthroughout the several figures, of which Figure l is acentral verticalsectional view of my improved chuck or holder, a tap being shown thereinin dotted lines. Fig. 2 is a transverse section on line 2 2 of Fig. 1,and Fig. 3 is a detail vertical sectional view of a slightly-modifiedform of sleeve forming one part of my improved chuck.

Referring in detail to the letters of reference marked upon thedrawings, A indicates the shank of my chuck, which in practice isinserted into the head of the spindle to drive the chuck and tap.

B indicate an annular flange around the base of the shank, and Crepresents the tapering frictional lower end. This lower portion, aswill be seen, is hollowed out, as at J, to receive the end of thetap-shank, as shown in dotted lines, Fig. 1.

An adjustable screw D is seated in a bore in the bottom of the hollow inthe shank, so that its head protrudes more or less into the hollowedportion and forms an adjustable stop for the shank of the tap. A,conical frictional bushing E encircles the tapering part C, and againstthis is placed the tap-carrying member or sleeve G, which, as shown, isshaped to correspond" to the taper of the bushing and lower end of theshank, asecond friction-piece E. in the form of a washer being placedbetween the flange B and the nut H covering the same. The upperperipheral surface of this sleeve is threaded to receive a nut H, whichhas aflange F to engage the flange B. On the sleeve is a lock-nut I toretain the nut H in place after the same has been adjusted. The sleeveGr contains a central opening J to receive a bushing K, which is securedto the sleeve by keys L, as shown. In practice smallsized taps areinserted in said bushing, while large sizes could be used without thebushing. If preferred, the bushing could be omitted, as shown in Fig. 3.A spring-actuated pin M serves to hold the bushing and tap in the sleeveby first passing through a hole in the former and engaging an annulargroove in the latter, as clearly appears in Fig. 2. A key N, carried bythe bushing, engages a slot in the shank to fix the same and impartrotary motion thereto. It will be seen that this construction andspecial assemblage of parts can be so adjusted and tightened as to drivethe sleeve and nuts with the shankwhen tapping a hole, for instancebutwill allow the shank to turn independently within the sleeve and nutswhen the tap meets with material resistanceas, for instance, by runningagainst the bottom of the hole it may be threading.

In practice the nuts H and sleeve are tightened only sufiiciently toafford a frictional engagement between the tapering end of the shank andthe sleeve to drive the tap in to cut a thread, but yet loose enough toinsure its slipping when the tap runs its thread and strikes the bottom,thus preventing injury to either tap or chuck. By properly adjusting thescrew D the direct inward thrust of the tap, which would otherwise be onthe sleeve G, is transferred to the shank A, thus preventing this inwardthrust from interfering with the adjustment of the frictional contactbetween the sleeve and the shank and preventing the sleeve from pressingany harder than necessary, on the conical frictional bushing E.

The long tapering bushing affords a particularly desirable friction,while the screw and bushing readily provides for difi'erent diametersand lengths of taps.

Having thus described my invention, what 1 claim, and desire to secureby Letters Patent, is

A drill-chuck of the character described,

comprising a shank provided with a tapering end having a hollow orrecess therein, a sleeve provided with tapering recess embracing thetapering end of the shank and having its bore in line with the recess inthe shank, a frictional conical sleeve between the tapering end of theshank and the sleeve, and a screw threaded into the shank in the bottomof the recess therein and adapted to receive the end thrust of a toolseated in and projecting through the bore of the sleeve, substantiallyas described.

Signed at Bridgeport, in the county of Fairfield and State ofConnecticut, this 4th day of September, A. D. 1903.

CHARLES R. PASCUCILLO.

Witnesses:

C. M. NEWMAN, W. V. Dnvrr'r.

